Shu's vitality, the loss of Jingzhou big injury, the battle of Yiling is to break themselves, but also just rely on the terrain advantage before the three-legged tripod.
Shu lost Jingzhou, after a Yizhou. Thirteen continents in the Three Kingdoms, Wei accounted for nine.
Changan, Luoyang and other places are very rich, Yizhou was poor, but also years of war. Not to talk about the late Shu no great generals, even the soldiers are poor, you can see the Three Kingdoms play can also be seen, fight the battle of Yiling, hundreds of thousands of troops, the northern expedition, are tens of thousands of thousands of deployments.
Even if Zhuge Liang can hit Hanzhong Tianshui and other places, and can hold it?
Not to say how Zhuge Liang, Shu is indeed weak, Sima consumed not only Zhuge Liang's vitality, but also the vitality of Shu.
Ugh, it's a pity.
As for the Meridian Valley, in the end there is a big debate on whether it works or not. But personally, I think it's worth a try, because Shu is relatively weak, and the more tor the more no advantage. Sima Yi himself said, if someone with a strange army out of the Meridian Valley, killed to Chang'an, the pattern of the three countries will be difficult to say.